(a) Field of the Invention
The present invention relates to an air hose assembly for a portable tire pump and having the dual function of air inflation and pressure release.
(b) Description of the Prior Art
In a conventional medium- or small-sized portable air pump for use in vehicles, the air hose assembly connected therewith works in a single direction, i.e., permitting air inflation only. With reference to FIGS. 1 and 2, an air hose assembly A10 is shown to include an abutting rubber ring A1, a hollow core A2, an air nozzle screw sleeve A3, a tightening ring A4, and an air hose A5.
During inflation, an air nozzle cap on the tire is removed, and the air nozzle screw sleeve A3 is screwably coupled to an outer screw sleeve of the air nozzle of the tire. At this time, insertion of the air nozzle screw sleeve A3 will simultaneously pushed the hollow core A2 to displace fowardly to directly press against an air core in the air nozzle of the tire. By means of the abutting rubber ring A1 at the front end of the assembly to abut against the air core, the latter is caused to open, so that compressed air generated as a result of operation of a piston of the air pump is pumped into the tire via the air hose A5 to inflate the tire.
During the process of inflation, the tire may be over-inflated inadvertently; the conventional air pump is generally provided with a pressure gage to indicate the pressure of the tire. In order to restore the pressure in the tire to a normal level, deflation to reduce tire pressure is required. To reduce the tire pressure, the user has to use a pointed object or his finger to press the air nozzle air core so that the pressure in the tire is released.
However, once the air hose assembly A10 is removed from the tire, it is no longer possible to read the tire pressure. Therefore, it is not known whether a suitable tire pressure has been released. That is, the tire pressure may be below normal or still be above normal. If the pressure released is excessive, the tire will need to be inflated again. It the pressure released is too little, the tire pressure remains high, which will endanger road safety. Furthermore, the conventional method of releasing the fire pressure is very slow and inconvenient, and the use may hurt his fingers or damage the air nozzle of the tire during release of tire pressure.